


The Thief in U.A.

by MypersonalityisDepresion



Category: Persona 5, 僕のヒーローアカデミア | Boku no Hero Academia | My Hero Academia
Genre: How Do I Tag, Kaminari Denki is Joker, Kaminari Denki is a Good Friend, Kaminari Denki-centric, Other Additional Tags to Be Added, Protective Aizawa Shouta | Eraserhead
Language: English
Status: In-Progress
Published: 2020-10-17
Updated: 2020-12-31
Packaged: 2021-03-08 21:29:00
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 5
Words: 4,561
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27053428
Author URL: https://archiveofourown.org/users/MypersonalityisDepresion/pseuds/MypersonalityisDepresion
Summary: What would happen if you gave tenagers a special power that could change a person for the better. What would happen if you also added Quirks to the mix? And what if the leader went to U.A the best hero School in Japan? Congratulations you have the vigilante group the Phantom Theives.~~~~Basically an au where Kaminari is Joker~~~~
Comments: 9
Kudos: 58





	1. Who am I?

**Author's Note:**

> I have never written anything before. So I would love some constructive criticism.
> 
> Also there will probably be some spelling errors.

A figure was thrown across the room. His tail coat bellowed as he was thrown. He landed with a resounding thud on the ground. He could hear cries of “Joker” coming from his teammates. 

He was low on health. He stood up glancing at his teammates. Mona looked tired from using his persona. Skull was getting in position to take the crown while Panther tried to distract Kamoshida. 

Joker ran back into the fight calling his persona as he went. He took a look towards Skull as he jumped to the king's crown. 

How did he manage to get here?

~~~~~ 20 days prior ~~~~~

Denki was having a bad day to say the least. He missed his alarm to wake up, he had a killer headache, AND he was late for his job interview. Could this day get any worse?

He rushed out of bed and got dressed as fast as he could. As he made his way downstairs he looked to his parents bedroom. Would his parents notice that he left? Probably not. After all, they never noticed before. After grabbing an energy bar, he continued onto the streets of Tokyo. 

Denki needed this job. He was just accepted into U.A the most prestigious hero school out there, But he lived in Tokyo not Musutafu. He needed the money to even get to the school. And he wanted some money he could spend on himself for once.

Making his way through the streets, He suddenly felt something hit his head pulling him out of his thoughts. When he looked up he noticed that it was raining. He cursed under his breath. Running to the nearest overhang seemed like the best option to him, at least for now.

He looked at his phone. Should he call the interviewer? Perhaps his parents could come and get him? He shook his head. What else could he do? He knew the subways were down due to an accident, so that's out of the question. Looking back at his phone he noticed a strange app. It had a red background with a strange eye on it. He glanced at the rain. He would probably be there for a while, so why not open the app.

While the app was loading, he looked up from his phone just in time to see someone join him under the canopy. As he glanced over he noticed that she had blond hair, blue eyes, and that she probably was in highschool.

She clearly noticed him staring because she nodded her head in hello. He nodded back. He should probably say hello out loud…

Suddenly a car pulled up. A middle aged man rolled down his window and spoke “Good Morning. Do you want me to drive you to school? You're going to be late.”

The girl spoke “Umm” she looked uncomfortable “sure. Thank you.” She made her way to the car and got in. The man and the girl drove away.

“Dang it. Screw that Perv teacher.” Denki was startled by this boy's out cry.

The boy looks peculiar to Denki. He was slouched, and was wearing the same uniform as the girl before. He had spiky yellow hair that was yellower than Denki’s hair. 

...Wait did he just say “Pervy teacher?” Denki accidentally said that last part out loud.

The boy turned to Denki cautiously “... What do you want? You planning to rat me out to Kamoshida?” the boy asked in a low tone.

“Who now?” Denki asked, shifting his stance to face the boy.

“That dude in the car just now. He’s Kamoshida. He’s always acting like the king of a castle.” the boy responded, hate written across his face.

“Ummm Which castle?” Denki asked not completely sure what this boy was talking about. He was certain that there were no castles near Tokyo.

The boy quieted down for a second. Confusion flashed across his face. ”You don't go to Shujin?”

Denki responded quickly shifting his feet again. ”No?” he paused and added, ”At Least I don't believe I go to Shujin?” 

The boy looked at him for a while, as if to analyze him. “Well the rain is letting up. Are you headed that way?” as he was speaking he nodded his head behind him.

“Actually yeah! I need to go that way..” Denki replied

“Cool you wanna walk with me?” 

“Sure! My name's Denki Kaminari by the way.”

As the boy turned around to walk away, he stated “My name is Ryuji Sakamoto.” the Boy stopped for a second “Ughhh I want to go home.”

The rain fell around them as they made their way towards their destination, making small talk as they went. They talked about their quirks and what highschool they went to. Ryuji told about Kamoshida to Denki. Until they made it to Shujin.

Ryuji was leading them. When he suddenly stopped. Denk, not noticing that he stopped, ended up walking straight into him. “What's the matter?” 

“What the?” Ryuji said.

Denki looked past him, and promptly took back everything he said about there being no castles in Tokyo.


	2. Am I not unique?

**Summary for the Chapter:**

> “I don't understand, Where’s the school?”

Denki looked past Ryuji, towards the castle. It was big, bigger than anything Denki has seen in his life. The castle was as wide as it was big, with trees lining the outside of the building. The stones looked carved with symbols. From where Denki was standing he could tell that the castle was old.

Ryuji looked back at him, twords where they came from, “we didn't go the wrong way. Why is this here”

Denki stared at the castle offering some input “maybe someone inside could tell us where we are.”

Denki started walking as Ryuji followed him into the castle.

As they entered Denki noted a chandelier hanging from the ceiling. Diamonds seemed to hang from the chandelier. Torches littered the sides of the walls, while paintings hung up of what looked to be like the teacher Ryuji mentioned. Ornate patterns littered the walls where pictures didn’t hang. Denki didn’t like it at all. It felt… wrong. 

“I don't understand, Where’s the school?” Denki said, glancing towards Ryuji as he spoke. 

someone walked towards them. 

It had a large shield at least as tall as Denki. It wore armor, but the face piece looked more like a mask than armor. He glanced to the side of the person, in its hand was a long sword that was very simple for such a huge castle. 

“Is that someone you know?” He asked not to take his eyes off of the person. It didn't feel human, it felt more wrong. Denki couldn’t find the word to describe it. 

“I don't think so.” Ryuji walked up to it. “Hey” it seemed like he was trying to get its attention. It must have worked because another walked up.

Denki looked to Ryuji, “Maybe we should get out of here.” He was cold, confused and scared, and those… things don't help with his mood either.

“Yeah.” as they started to walk away some more things cut them off.

“What is with these guys?” Ryuji mumbled. 

Suddenly one attacked. It went for Ryuji, he couldn’t dodge or move out of the way so he was hit with its shield. He fell to the ground in shock. Denki tried to use his quirk but it just kept bouncing off the armour. Once he figured out that didn’t work, he tried to kick it. But that didn't work either. He was suddenly overpowered by them.

Denki felt useless. 

The first thing Denki could hear when he got up was Ryuji shouting at him. He reluctantly sat up.

The first thing Denki saw when he sat up were chains, Denki did not take that as a good sign. He absentmindedly asked “where are we.”

Ryuji was quick to respond, “I don't know man, but it looks like we're in some sort of dungeon.” 

Denki took a better look around the room. It was Dark, the only light coming from torches along the wall. Towards his right he could see chains scattered across the wall. In the opposite direction there were barrels. He glanced down towards the front of the room. They seemed to be behind bars. 

Denki was pulled out of his thoughts as he heard someone scream. 

He ran as fast as he could to see if he could see anyone outside. He stole a look towards Ryuji who was in shock. 

They needed to get out of here.

He tried to open the door. It was locked. “Ryuji, Check the barrels. See if there is anything in there.” He spoke as he took strides towards the chains on the walls. They needed to find something, anything that could help them escape.

Then he heard it. Footsteps were coming towards them. Denki’s heart pounded in his chest as he slowly looked to the bars.  
“Your punishment has been decided upon.”

One of those armored things walked towards them

“For unlawful entry you shall receive the punishment of death.” it was not alone. It seemed that there were at least 2 other things with it. Denki couldn’t take them, neither could Ryuji. Denki glanced around. There must be some way out of this prison. His eyes landed to the back of the cell.

“ No one can just do as they please in MY castle.” Someone spoke. He heard Ryuji gasp. He turned his head towards the front of the room. Standing there was Kamoshida in all his glory. He was wearing… Practically nothing.

“O my go-” Denki was cut off by Kamoshida “SHUT UP THIEVES” 

“To think the person robbing my palace was you Sakamoto. How foolish of you.” Kamoshida stated. Denki didn’t like him. “AND you brought a friend to help you.” Kamoshida looked to Denki. 

“WHAT IS GOING ON YOU ASS” Ryuji shouted. Kamoshida took his attention off of Denki.

“Is that how you treat your KING.” He unlocked the door to the cell. He walked slowly speaking as he walked. “NOT only did you break into MY castle.” his voice rose with every step he took.”BUT you INSULTED me the KING.” he stood in front of Ryuji ordering his guards to come in. 

“The punishment for that is Death.”

The one of the guards pinned Ryuji to the wall. The other two held Denki back. He struggled to get out of the grasps of the guards to help his friend, but he couldn’t escape them. All he could muster was a faint “Stop it.”

“Be prepared after all you're the next one to die.”

The guard healed Ryuji up. Denki tried everything he could think of to get out of the grasp of the guards.

He tried kicking the guards… nothing happened 

He tried his quirk… it bounced off of both the guard’s armor.

He even tried punching the guards… the only thing that achieved was a bruise on his hand.

Denki was freaking out. He looked everywhere in the room looking for something that could help his friend. Any way he could break free from the guards.

That's when he heard it

“Are you simply going to stand there and watch?”


	3. Maybe I'm not Here at All.

**Summary for the Chapter:**

> _“Death awaits him if you do nothing.”_

_“Are you simply going to stand there and watch?”_

Denk looked around for the voice. It sounded like it was coming from everywhere in the room.

_“Are you forsaking him to save yourself?”_

_“Death awaits him if you do nothing.”_

_“Was your decision to become a hero,a mistake?”_

Memories of his parents flash through his mind. Everything he has suffered up until now.

“It wasn’t”

The guard raised Ryuji up high. Denki looked around.

He needed something. He struggled to get out of the grasp. Looking around one more time and seeing nothing made his determination falter, But he still tried. He needed something stronger than a quirk. He needed something powerful. Something to escape this prison.

“ _Very well. I have headed your resolve_.”

Everything stopped

Pain filled his body. His blood was lava flowing through his body. Needles filled his lungs. His vision was blurring with the black spots dancing around it. His head was about to break, like an egg being cracked open.

“ _Vow to me. I am thou, thou art I”_

His legs and arms were tearing at the seams. His heart was beating too loud, he could hear it in his ears. The black spots got bigger as everything became white from the pain.

“ _Thou art willing to perform all sacrilegious acts for thine own justice! NOW call upon me and RELEASE YOUR RAGE_!”

He screamed

“ _Show the strength of thy will to ascertain all thy own. Though thou be chained to hell itself!”_

“Execute him!” Denki looked up as the false king spoke.

“I will stop you.” he stared down the king. He had enough of this king’s bulshit. How dare he treat Ryuji like a stress ball.

Kamoshida turned around.” What was that.” He looked at Denki and nodded his head “You want to be killed first. Fine by me. Guards!”

He was suddenly aware of something hitting his face. He was held against the wall as the Guard was preparing his sword. He saw Ryuji try to get up.

As the guard lifted his blade, He suddenly felt power in him. It was like he could do so much, everything he ever wanted. It felt like his quirk, but SO much better.

Then it was suddenly taken away.

Something was on his face. It stopped him. He hated the feeling. It was like he was weak all over again. Everything was taken away. It was confining. How could he get it back. WHAT DOES HE NEED TO DO.

He reached up to his face and he thought for a moment. If the mask stopped him, what if he took it off?

He pulled.

It wouldn’t come off

He pulled harder.

It suddenly started ripping off.

That's the answer he just needed to pull it HARDER.

With a scream, the mask came off. a magnificent stream of blood followed his face as he looked to the floor. Even though he used all of his energy to pull it off, he felt good. Like he was finally let out of a cage he was trapped in.

He looked up.

Fire consumed him. His quirk was going crazy. It felt amazing.

The fire started dying down as someone stood up behind him.

Denki waved his arm. Razor sharp air rushed past him. Somehow not injuring him.

Guards flew away from him. They were pushed back by the air. Barrels slammed against the wall, breaking upon impact. Kamoshida was thrown back with the guards, but he fled a long time ago. Ryuji stared at him, fear and admiration spread across his face. Denki could hear terror in his voice as he spoke.

“What the?”

Denki looked at his hands.

That was strange. He could have sworn he wasn't wearing gloves when he walked into this castle. And he could have also sworn he wasn’t wearing boots and a long trench coat. Wait a minute… WHAT HAPPENED TO HIS CLOTHES?

Some movement behind him drew him out of his thoughts. He turned around and saw… wait. WHY WAS THERE A BIRDMAN BEHIND HIM? WHERE DID IT COME FROM?

The bird dude spoke. “I am Arsene, the Pillager of Twilight.”

Denki was shocked. THE BIRD SPOKE.

Arsene chuckled, “I am not a bird Kamanari.”

The Bird, no, Arsene had a lot of red. His coat was red. His pants were red. His long boots were red. He had large black wings that were folded up. His black hat reached to the ceiling and he had long claws. Blue fire danced around Arsene as he looked towards Denki. If he was being honest, Arsene kinda looked like a demon.

Hold up. DID IT JUST HEAR HIS THOUGHTS?

“I am the rebel soul that dwells within you, Kaminari Denki.” Denki looked to Arsene. “If you so desire, I shall grant you the power to push through this crisis.”

Denki took time to consider his options. Those guards don’t seem to be fazed by his attacks, maybe Arsene can actually do some damage. On the other hand Arsene could be evil.

Denki stared at him. “GIve me your power.”

Denki felt Arsene smile. “Very well.”

“Who the hell are you.” Denki looked towards kamoshida. He looked angry, like someone just spoiled his fun game. “Guards kill that one first.”

The guards started melting. Red and black puddles formed on the ground. Denki heard Ryuji mumble from his spot on the floor, something about hell and monsters. The puddles started reforming into something.

“Now you'll learn of my true strength.” the king said.

The guards now looked like… Floating pumpkins?

“This strength of mine is now yours.” Denki looked to Arsene as he spoke. “You see those guards?” Denki nodded his head. “Detest them with all your soul. Then use that hatred and form it into power. Then unleash it.” Denki looked towards the enemy. These dudes just tried to kill him and hurt his friend. Why should he like them?

He felt power growing. It was like his quirk but… different. It felt more like him. He knew what to do. He felt a word come to mind.

“Arsene, use Eiha!” He felt Arsene snap his claws behind him. Red strings came up from beneath the pumpkin person. Until it all exploded.

“Here, take this wepn and finish it off.” Arsene handed Denki a long blade. It had small writing on the blade that Denki couldn't read.

Denki ran up to the hurt pumpkin and attacked. His tail coat flailed as he jumped. As his blade made a clean cut. The pumpkin exploded into a black cloud.

“Be careful Kamanari, It is their turn to attack.” Denki looked just in time to see the other pumpkin attack him. He just barely dodged it.

“Now kill the last one in whatever way you like.”

He chose to attack the pumpkin dude using his weapon once and he finished it off with Arsene. Denki would be lying if he said he didn’t like killing these dudes.

“What was that just now?” He looked to Ryuji. Ryuji didn’t bother getting up from his spot on the floor. It was when Kamoshida came back into the room, when he decided to move. He cut Kamoshida off and slammed into him knocking Kamoshida to the floor.

“TAKE THAT YOU ASS!”

“Ryuji the keys!”

Ryuji grabbed the keys from off the floor and ran out with Denki. They proceeded to lock the door to stop Kamoshida from coming out. As they ran away from Kamoshida's yelling Denki noticed that his ataire had changed back to his normal clothes. It seemed like Ryuji also noticed his change in clothes

“Woah, what happened to your fancy clothes and mask?

“I don’t know dude? My bigger question is how do we get out of here?”

Someone spoke from behind him. “Blondie! Electric Hair! Look over here!

**Notes for the Chapter:**

> I'm glad you guys like this story! 
> 
> I'm thinking the next chapter will be out by the 15th


	4. Look, the fakers.

Denki turned around to see a cat? A cat wearing a yellow bandana around its neck.

“What is this thing!” Exclaimed Ryuji. If Denki had to take a guess, he would say it was a cat with humanoid features. 

“You're not the castle guards are you?” Denki decided to call it a cat. “Look, the keys are right over there! Get me out!!” 

He turned to where it was pointing at as Ryuji spoke to the cat. It wouldn’t hurt to let it out right? What's the worst that could happen. In the background he could hear Ryuji ask why they should trust the cat.

After telling the cat to quiet down he walked over to the keys and grabbed them. “Can you show us the way out?”. Once the cat gave a nod he inserted them into the keyhole and opened the door. “You better not be lying, you got that.”

“Ahhh sweet sweet freedom at last.”

“Now, show us the exit you monster cat!” Ryuji exclaimed loudly. Denki quickly shushed him.

“I’m NOT a CAT!” the not cat exclaimed. “I am Morgana.” So the cat had a name that's nice. But that still doesn’t explain why he can talk. Perhaps it's a quirk.

“Hurry up and show us the way out. DO you want to get locked up again?” Ryuji glared at Morgana.

“Fine, but you have to stay quiet. We don't need them hering you.” Morgana walked ahead faster than the two boys. Denki followed the Cat closely while Ryuji followed Denki. He led them to a statue of Kamoshida that was right next to a drawbridge. He looked like he expected them to do something. Denki was beyond confused at this point. 

Ryuji spoke before Denki could question anything. “Why did you stop here?” 

“I’m lowering the bridge. Hey electric hair Feel around the Front of the statue. See if there's a lever you can pull.”

Denki doesn’t know if he should feel insulted by a cat calling him electric hair. Despite how much he wanted to do the complete opposite of what the cat said, they still needed to get out of here. So he reluctantly felt around the mouth of the Kamoshida statue.

He kept feeling around until… he pulled the jaw down.

Wow the cat was right. There really was a lever in the statue.

The bridge started to lower. heard Ryuji shout and he heard Morgana shout something about being an amature. Morgana started walking across the bridge, so Denki followed him. It's not like there was any other choice. He could try to get Arsene to come back out, but he doesn’t even know what he did the first time. Perhaps he could get that mask back on his face again?

Denki was brought out of his thoughts when he felt his clothes change. He looked down to see his gloves red again. He heard Ryuji scream. In front of them were two MORE guards. He saw Morgana jump over Ryuji towards the guards.

“Hey electric hair. You can fight right?” Denki nodded his head.

“Good.” Morgana stepped forwards. “Come Zoro!” When Morgana said that a figure appeared behind him. It had a cape that waved even though there was no wind. It had some kind of face with a mustache. To Denki it looked cool, but he still thinks Arsene looked cooler.

Denki walked with Morgana into the battle.

The guards once again turned into puddles, which then transformed into weird monster things. One was the good old pumpkin dude again, while the other was a demon. Yeah lets just leave it at that.

Morgana struck at the demon, while he headed towards the pumpkin dude.

**Notes for the Chapter:**

> Sorry this chapter isn't that long, life kinda got in the way. 
> 
> the next chapter probably will come out next Saturday, hopefully.


	5. Binding Us with Lies

Surprisingly the battle went by fast and they ran from the sight of the fight.

They ran through the dungeon’s twisting passageways. Their footsteps echoed through the hallway,as they followed Morgana. 

Cells lined the hallways, filled with people Denki didn’t know. Some were crying, others were screaming. A lot of them had injuries. Others didn’t have any, but all of them had one thing in common. They all looked defeated. 

He wanted to help the people in the cells, but they didn’t have time. It's either they get out alive or they die. They could fight one of those monsters, but he doesn’t think it would go well, he doesn’t even know if he could summon Arsen again.

Maybe they could come back for them.

Denki hated that they had to leave them behind.

The dungeons started changing into the main castle as they ran. The walls were no longer barren, pictures of Kamoshida decorated them. The floor started to look less dirty and at some parts even had carpet. Statues became more prominent.

They ran through the castle until they came upon a room.

Denki turned to Morgana as he spoke. “Were finally here!”

He let out a sigh of relief. Soon he would be out of this castle and he would be heading towards his job interview. He would get the job. He would head home and head straight to his room and go to be-

“You tricked us you jerk!”

WHat.

Denki looked to Ryuji. He could not have just said that. Did he try the door? Maybe he’s pulling a prank on them. 

He walked to the door. His quirk buzzed inside of him anxiously. Ryuji was next to him. He put his hand on the door knob and tried turning it.  
It was locked.

Damn it.

He turned towards the cat. You know what, there’s probably a great recipe for a cat stew online. 

Morgana scoffed “Don't be such idiots. Come this way”

They followed the Cat towards an open room. There was a bookcase in front of them. To their left were two large torches hanging on the wall. To his right was a table with four chairs. There was nothing else in the room. There were no windows or doors.

Ryuji spoke “Um, question cat.” 

“I’m not a cat”

“Where is the exit?”

It was silent for a few seconds. 

“Amature, This is the easiest thing to remember.”

Ryuji turned to Denki “I’m so lost.”

“Same ” 

He turned towards the shelf. What could the Cat mean? Maybe he meant we're making our own exit or this is one of those old movie moments where they sneak through a vent. Like in spy kids. 

Now that he started to think about it, there did seem to be some sort of vent above the shelf.

“Maybe we could use that vent up there?” He pointed to the vent 

“Good job, that’s exactly what we're going to use.” Somehow the cat looked smug. “It leads all the way outside.” 

“Finally we're gonna get outta here.” 

“Great” Denki climbed the shelf to get to the vent. The vent was cold to the touch.He pried the grey cover off and climbed through. Ryuji followed behind him.

~~~~~

When they got out of the castle the first thing Denki noticed was there was no castle around them. The second thing he noticed was the cat didn’t come with them. 

“Did we make it?” 

Denki didn’t look at Ryuji. He opted to instead look at his surroundings. His phone sounded off something about returning to the “real world”

“It seems like it. I only have one question.”

Ryuji made a hum. Denki continued.

“What the hell was that.”

Ryuji stood up.``I don't know what to think anymore.” He stared at Denki “ There was a Castle, Kamoshida and a talking cat. A TALKING CAT. Who knows how long we were in there for.”

Ryuji brings up a good point. They were probably in there for a while. 

He checked the time.

You have got to be joking. He was late. For the EXTREMELY IMPORTANT interview.

“Shit, I have to go.Maybe we could go back to the castle later.” Denki started running but he stopped. “Can I get your number? Maybe we could chat about what just happened.”

“Sure” Ryuji bounced on his heels. “I can write it down for you. Give me a second.” He pulled out a notebook from his bag. “Here.”

Denki took the paper. “Thanks. I guess i'll see you later?”

“Yeah, bye.” Ryuji turned around, his bag swinging on his shoulder as he walked away from Denki. Denki ran in the opposite direction towards his interview.

**Notes for the Chapter:**

> Merry Christmas and a happy new year!!
> 
> So I realize that I said I would update this a long time ago, sorry about that.


End file.
